In November, we learned that the National Highway Traffic Safety Administration had opened an engineering analysis into a potential defect with Tesla’s popular Models S and X battery electric vehicles. On Wednesday, the other shoe dropped, when NHTSA informed the American automaker that it has to recall 158,000 vehicles to fix defective touchscreens.
The problem concerns a component in the vehicles’ infotainment systems, called the Media Control Unit. Buried within the MCU is an 8GB eMMC NAND flash memory chip, which can only be written to a finite number of times. Once this number of read/write cycles is reached—something that takes between three and four years depending on how much the car is driven—the touchscreen dies. And unfortunately, that’s a real problem in a car where the touchscreen is the way almost all the controls are accessed.
Not being able to browse the Internet in your car or stream a podcast is obviously an inconvenience, especially in an high-end vehicle. But NHTSA is more concerned about the fact that if the touchscreen dies, functions like the backup camera and window defogging are lost, too, as are audible alerts for other onboard safety systems.
The problem is well-known among the Tesla community, affecting any Model S built between 2012 and 2018, and Model Xs built between 2016 and 2018. After NHTSA received 537 complaints from owners it asked Tesla if it had more information on the scope of the problem. It did—handing over records of thousands of complaints and more than 12,000 MCU replacements.
Now, NHTSA has taken the unusual steps of telling Tesla it must recall the 158,000 affected vehicles, according to Reuters. “[D]uring our review of the data, Tesla provided confirmation that all units will inevitably fail given the memory device’s finite storage capacity,” NHTSA told Reuters. NHTSA also noted that Tesla had attempted to resolve the issue with software patches, but these have been “procedurally and substantially insufficient” and the law requires automakers to recall vehicles that contain safety defects.
Tesla has no press office to contact for a comment, and the company has not made a statement on either its Twitter feed or that of CEO Elon Musk’s. The company has since redesigned the MCU to use a 64GB eMMC, so more recent vehicles should not be affected. The more popular Models 3 and Y are unaffected by this issue.